(CLV) And sighing in His spirit, He is saying, "Why is this generation seeking for a sign? Verily I am saying to you, If there shall be given to this generation a sign!"

Acts

Acts 19:20

(KJV) So mightily grew the word of God and prevailed.

ουτως κατα κρατος ο λογος του κυριου ηυξανεν και ισχυεν

κυριου is always in every other place translated "Lord," whereas "God" in all other places is translated from θεος. The KJV translators were following the precedent set by Wycliffe and Tyndale even though all of them were in error.

(ASV) So mightily grew the word of the Lord and prevailed.

Ephesians

Ephesians 3:21

(KJV) Unto him be glory in the church by Christ Jesus throughout all ages, world without end. Amen.

The KJV fails to translate "του αιώνος των αιώνων" as "the age of the ages" and instead has "world without end." The KJV also omits translating γενεάς as generations and instead has "throughout all ages."

(YLT) to Him is the glory in the assembly in Christ Jesus, to all the generations of the age of the ages. Amen.

I Corinthians

I Corinthians 15:4

(KJV) And that he was buried, and that he rose again the third day according to the scriptures:

και οτι εταφη και οτι εγηγερται τη τριτη ημερα κατα τας γραφας

"Rose" which is in the past tense, is the incorrect tense of the underlying greek verb. The Greek word εγηγερται is in the perfect, passive, indicative, third person, singular. A correct translation would be "was raised."

(ABP) and that he was entombed, and that he was raised in the third day, according to the scriptures;

Hebrews

Hebrews 3:11

(KJV) So I sware in my wrath, They shall not enter into my rest.

ως ωμοσα εν τη οργη μου ει εισελευσονται εις την καταπαυσιν μου

ει is translated as the negative "no" instead of "if." In Hebrews 4:3 and 4:5 ει is translated properly as "if."

(YLT) so I sware in My anger, If they shall enter into My rest--!'

James

The name James is an incorrect translation of the Greek name ιακωβος and should be Jacob.

Jude

Jude 1:12

(KJV) These are spots in your feasts of charity, when they feast with you, feeding themselves without fear: clouds they are without water, carried about of winds; trees whose fruit withereth, without fruit, twice dead, plucked up by the roots;

σπιλαδες is translated as spots instead of reef or rock. The KJV translators confused σπιλάς, a reef, with σπίλος, a spot or stain.

(Geneva) These are rockes in your feasts of charitie when they feast with you, without al feare, feeding themselues: cloudes they are without water, caried about of windes, corrupt trees and without fruit, twise dead, and plucked vp by ye rootes.